Note 5 - Loans and Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Valuation allowance	$ 1,151		$ 1,096
Loans recorded balance	11,435		11,968
Loans unpaid principal	12,668		13,201
Loans average investment in impaired loans	10,440	$ 19,266
Loans interest income recognized	2	5
Residential Portfolio Segment [Member] \| Real Estate Residential, One To Four Family Units [Member]
Loans without a specific valuation allowance, recorded balance	967		1,392
Loans without a specific valuation allowance, unpaid principal	967		1,392
Loans with a specific valuation allowance, recorded balance	1,170		1,221
Loans with a specific valuation allowance, unpaid principal	1,170		1,221
Valuation allowance	184		197
Loans recorded balance	2,137		2,613
Loans unpaid principal	2,137		2,613
Loans without a specific valuation allowance, average investment in impaired loans	1,091	1,079
Loans without a specific valuation allowance, interest income recognized		1
Loans with a specific valuation allowance, average investment in impaired loans	1,173	3,011
Loans with a specific valuation allowance, interest income recognized
Loans average investment in impaired loans	2,264	4,090
Loans interest income recognized		1
Residential Portfolio Segment [Member] \| Real Estate Residential, Multi Family Units [Member]
Loans without a specific valuation allowance, recorded balance
Loans without a specific valuation allowance, unpaid principal
Loans with a specific valuation allowance, recorded balance
Loans with a specific valuation allowance, unpaid principal
Valuation allowance
Loans recorded balance
Loans unpaid principal
Loans without a specific valuation allowance, average investment in impaired loans		5,938
Loans without a specific valuation allowance, interest income recognized
Loans with a specific valuation allowance, average investment in impaired loans
Loans with a specific valuation allowance, interest income recognized
Loans average investment in impaired loans		5,938
Loans interest income recognized
Residential Portfolio Segment [Member] \| Construction Loans [Member]
Loans without a specific valuation allowance, average investment in impaired loans
Loans without a specific valuation allowance, interest income recognized
Loans with a specific valuation allowance, average investment in impaired loans	3,939	3,805
Loans with a specific valuation allowance, interest income recognized
Loans average investment in impaired loans	3,939	3,805
Loans interest income recognized
Real Estate, Construction [Member]
Loans without a specific valuation allowance, recorded balance
Loans without a specific valuation allowance, unpaid principal
Loans with a specific valuation allowance, recorded balance	4,424		4,742
Loans with a specific valuation allowance, unpaid principal	5,657		5,975
Valuation allowance	596		553
Loans recorded balance	4,424		4,742
Loans unpaid principal	5,657		5,975
Commercial Real Estate Portfolio Segment [Member]
Loans without a specific valuation allowance, recorded balance	2,929		3,199
Loans without a specific valuation allowance, unpaid principal	2,929		3,199
Loans with a specific valuation allowance, recorded balance	521		162
Loans with a specific valuation allowance, unpaid principal	521		162
Valuation allowance	32		24
Loans recorded balance	3,450		3,361
Loans unpaid principal	3,450		3,361
Loans without a specific valuation allowance, average investment in impaired loans	2,765	3,472
Loans without a specific valuation allowance, interest income recognized		4
Loans with a specific valuation allowance, average investment in impaired loans	281	726
Loans with a specific valuation allowance, interest income recognized
Loans average investment in impaired loans	3,046	4,198
Loans interest income recognized		4
Commercial Portfolio Segment [Member]
Loans without a specific valuation allowance, recorded balance	17		33
Loans without a specific valuation allowance, unpaid principal	17		33
Loans with a specific valuation allowance, recorded balance	1,104		999
Loans with a specific valuation allowance, unpaid principal	1,104		999
Valuation allowance	314		301
Loans recorded balance	1,121		1,032
Loans unpaid principal	1,121		1,032
Loans without a specific valuation allowance, average investment in impaired loans	19	232
Loans without a specific valuation allowance, interest income recognized
Loans with a specific valuation allowance, average investment in impaired loans	904	667
Loans with a specific valuation allowance, interest income recognized
Loans average investment in impaired loans	923	899
Loans interest income recognized
Consumer and Other Loans [Member]
Loans without a specific valuation allowance, recorded balance	114		70
Loans without a specific valuation allowance, unpaid principal	114		70
Loans with a specific valuation allowance, recorded balance	189		150
Loans with a specific valuation allowance, unpaid principal	189		150
Valuation allowance	25		21
Loans recorded balance	303		220
Loans unpaid principal	303		$ 220
Consumer Portfolio Segment [Member]
Loans without a specific valuation allowance, average investment in impaired loans	99	216
Loans without a specific valuation allowance, interest income recognized	2
Loans with a specific valuation allowance, average investment in impaired loans	169	120
Loans with a specific valuation allowance, interest income recognized
Loans average investment in impaired loans	268	336
Loans interest income recognized	$ 2

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

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